An anonymous tipster tried to fool Page Six into believing de Lesseps and fiancé Thomas D’Agostino Jr. slipped into a bathroom stall in NYC’s Regency Hotel, where the sketchy “source” claimed that de Lesseps performed an unspeakable sex act on him for 45 minutes, while “audible moans” and “whispering in French” could be heard.

Sources close to de Lesseps claim that Frankel’s allies are behind the tasteless tale.

Frankel’s feud with de Lesseps exploded again on the Bravo show after Frankel revealed that D’Agostino kissed another woman, and de Lesseps returned fire by claiming that Frankel hooked up with her now-boyfriend, Dennis Shields, before he was separated from his wife, which Frankel denies.

De Lesseps told us she was away at a funeral in Philadelphia when the fantasy tryst was supposed to have taken place, adding: “Obviously a desperate attempt by the Housewives camp to ruin my reputation and my upcoming marriage. Not going to happen! It’s really sad how desperate these women can be. I think the show should be renamed ‘The Desperate Housewives.’”